Considerable volumes of crude oil are produced from off-shore facilities, whether from platforms or from subsea wellheads. Production of crude oil from these facilities typically requires that the crude oil be transported to on-shore facilities through pipelines. Additionally, crude oil and refined hydrocarbon products are often transported across bodies of water through subsea pipelines. These subsea pipelines are designed and installed to operate with a low probability of failure because of the high cost of repairing such failure and because of the desire to minimize any environmental impact resulting from such a failure. In spite of this low probability of failure, it is still desirable to further minimize the consequences of a failure of a subsea pipeline.
It is therefore an object of the present invention to provide a subsea pipeline wherein the amount of oil leaked from the pipeline is reduced. It is a further object to provide such a pipeline that can be installed, pigged, and otherwise operated in a conventional manner.